1,620 research outputs found
Investigation of single crystal ferrite thin film Semiannual report, 1 Feb. - 31 Jul. 1969
Vapor deposition of single crystal thin films of lithium ferrite utilizing ferric chlorid
Investigation of single crystal ferrite thin films
Materials suitable for use in magnetic bubble domain memories were developed for aerospace applications. Practical techniques for the preparation of such materials in forms required for fabrication of computer memory devices were considered. The materials studied were epitaxial films of various compositions of the gallium-substituted yttrium gadolinium iron garnet system. The major emphasis was to determine their bubble properties and the conditions necessary for growing uncracked, high quality films
Rites of Passage: Debutante Balls in Filipino-American Culture
The debutante ball is a traditional Western ritual often designed to celebrate young women’s transition from childhood to adulthood. The word debut (i.e., to enter into society) comes from French language but came into use by the English during the reign of King George the 3rd (1760- 1820). From 1837 on, the young women were referred to as debutantes later shortened to debs (Haynes, 2005)
Effect of Strain of Holstein-Friesian Cow and Feed System on Reproductive Performance in Seasonal-Calving Milk Production Systems Over Four Years
In Ireland most dairy farms operate seasonal calving grass-based milk production systems. Feed demand and supply are matched by having calving highly concentrated in spring. This requires high pregnancy rates within a short time following the start of mating in late April or early May, but has become increasingly difficult to achieve due to declining fertility in Irish dairy herds (Mee, 2004). In New Zealand, cows of North American Holstein-Friesian origin have poorer fertility than New Zealand Holstein-Friesians on pasture-based seasonal calving systems (Harris & Kolver, 2001). The present study sought to determine the effect of strain of Holstein-Friesian (HF) cow and feed system on reproductive performance within Irish milk production systems
Influence of prebreeding progesterone plus prostaglandin F2-α on estrus and fertility in lactating dairy cows
Progesterone administered before breeding may increase estrous expression and subsequent fertility in lactating dairy cows. Holstein cows (n=302) were assigned randomly at calving to three groups. Cows received no treatment (controls), one injection of prostaglandin F 2-α (PGF), or progesterone plus one injection of PGF (PRID + PGF). The average interval to estrus was 5 days shorter in PRID + PGF cows compared to cows given only PGF. In addition, more cows were observed in estrus 2 to 5 days after treatment in the PRID + PGF group compared to the PGF group. Average days from calving to conception were reduced in PRID + PGF cows by 15 to 20 days compared to control and PGF cows. We concluded that prebeeding progesterone in combination with PGF appears to enhance fertility.; Dairy Day, 1987, Kansas State University, Manhattan, KS, 1987
Simulation of the Performance of the IISc Chemical Kinetics Shock Tube
This report presents the results of an investigation of the performance of the Chemical Kinetics Shock tube at the Indian Institute of Science. The one-dimensional Lagrangian code L1d of Jacobs (1998) has been used to simulate the tube at several operating conditions. The conditions have different shock tube filling pressures, resulting in different shock speeds and different tube lengths, resulting in different dwell times. The simulations have been performed both with and without viscous effects simulated in the tubes. At the lowest shock tube filling pressure condition, the shock tube operates in an overtailored mode and it is undertailored at the higher filling pressure conditions. The results show that viscous effects, which lead to attenuation of the primary shock and heat loss from the test gas to the tube walls, result in an increasing p5 pressure during the test time. The viscous effects are more dominant at the condition with the lowest filling pressure (highest primary shock speed). A simulation run for 50 ms after diaphragm rupture or the configuration with a long driver tube shows that the test gas is periodically re-compressed by reflections of waves along the driver and shock tubes. The recompressions become sequentially weaker and thus the test gas temperature and pressure are never raised to as high levels as for the primary compression
Simulating field-aligned diffusion of a cosmic ray gas
The macroscopic behaviour of cosmic rays in turbulent magnetic fields is
discussed. An implementation of anisotropic diffusion of cosmic rays with
respect to the magnetic field in a non-conservative, high-order,
finite-difference magnetohydrodynamic code is discussed. It is shown that the
standard implementation fails near singular X-points of the magnetic field,
which are common if the field is random. A modification to the diffusion model
for cosmic rays is described and the resulting telegraph equation (implemented
by solving a dynamic equation for the diffusive flux of cosmic rays) is used;
it is argued that this modification may better describe the physics of cosmic
ray diffusion. The present model reproduces several processes important for the
propagation and local confinement of cosmic rays, including spreading
perpendicular to the local large-scale magnetic field, controlled by the
random-to-total magnetic field ratio, and the balance between cosmic ray
pressure and magnetic tension. Cosmic ray diffusion is discussed in the context
of a random magnetic field produced by turbulent dynamo action. It is argued
that energy equipartition between cosmic rays and other constituents of the
interstellar medium do not necessarily imply that cosmic rays play a
significant role in the balance of forces.Comment: 11 pages, 12 figures, a major revision; accepted for publication in
MNRA
Exact Solutions to the Sine-Gordon Equation
A systematic method is presented to provide various equivalent solution
formulas for exact solutions to the sine-Gordon equation. Such solutions are
analytic in the spatial variable and the temporal variable and they
are exponentially asymptotic to integer multiples of as
The solution formulas are expressed explicitly in terms of a real triplet of
constant matrices. The method presented is generalizable to other integrable
evolution equations where the inverse scattering transform is applied via the
use of a Marchenko integral equation. By expressing the kernel of that
Marchenko equation as a matrix exponential in terms of the matrix triplet and
by exploiting the separability of that kernel, an exact solution formula to the
Marchenko equation is derived, yielding various equivalent exact solution
formulas for the sine-Gordon equation.Comment: 43 page
Scramjets and Shock Tunnels: The Queensland Experience
This article reports on the use of a shock tunnel to study the operation of scramjet powered configurations at sub-orbital velocities above 2 km/s. Thrust, as given by a net thrust equation, is used as a figure of merit throughout the study. After a short description of the shock tunnel used and its operating characteristics, experiments on the combustion release of heat in a constant area duct with hydrogen fuel are reviewed. The interaction between heat release in the combustion wake and the walls of the duct produced pressure distributions which followed a binary scaling law, and indicated that the theoretically expected heat release could be realized in practice, albeit with high pressure or long combustion ducts. This heat release, combined with attainable thrust nozzle characteristics and a modest level of configuration drag, indicated that positive thrust levels could be obtained well into the sub-orbital range of velocities. Development of a stress wave force balance for use in shock tunnels allowed the net thrust generated to be measured for integrated scramjet configurations and, although the combination of model size and shock tunnel operating pressure prevented complete combustion of hydrogen, the cruise condition of zero net thrust was achieved at 2.5 km/s with one configuration, while net thrust was produced with another configuration using an ignition promoter in hydrogen fuel. Nevertheless, the combination of boundary layer separation induced inlet choking and limited operating pressure levels prevented realization of the thrust potential of the fuel. This problem may be alleviated by recent increases in the shock tunnel operating pressures, and by promising research involving inlet injection of the fuel. Research on the drag component of the net thrust equation resulted from the development of a fast response skin friction gauge. It was found that existing theories of turbulent boundary skin friction predicted the skin friction when combustion of hydrogen occurred outside the boundary layer, but combustion within the boundary layer dramatically reduced the skin friction. Finally, for the first time in the world, supersonic combustion was produced in a free flight experiment. This experiment validated shock tunnel results at stagnation enthalpies near 3 MJ/k
Keeping Customers Shopping in the Store: Interrelationships among Store Attributes, Shopping Enjoyment, Place Attachment, and Store Loyalty
With consumers shifting to Internet and mobile shopping, the demand for brick and mortar store shopping has decreased and in response, several major U.S. retail chains have downsized the number of their physical retail operations (Farfan, 2013). Yet, retailers have not completely said good bye to stores. Indeed there may be several key store attributes that retailers’ can focus on and continue to develop if they are interested in keeping customers shopping and buying in brick and mortar stores
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